Outdoor cooking apparatus, such as gas barbecue grills, can require design criteria different than cooking apparatus designed for indoor use. For example, during periods of non-use, barbecue grills are exposed to weather, blowing dust, debris and insects. These elements can seriously affect the performance of gas-fueled burners. Furthermore, during use, wind and precipitation can seriously affect flame performance in gas-fueled burners, as the flow of air/fuel mixture may not be sufficiently robust enough to avoid partial or total extinguishment of the flame.
Conventional gas burners for outdoor applications are designed such that the primary combustion air intake occurs upstream of the gaseous fuel inlet, where the gas orifice is located. In general, the opening or openings through which primary air enters the combustion chamber allows insects, mostly spiders, to crawl into the gas mixing chambers. This can lead to either partially or completely closing the gas orifice and obstructing flow in the gas mixing chamber. The combination of dust, debris and insects which clog up the gas orifice or gas mixing chamber make it necessary for the user to periodically clean these areas. However, when a conventional gas burner is mounted to a work or mounting surface of a barbecue grill, the combustion air intake is accessible only from underneath the mounting-top surface. This makes it extremely inconvenient for the user to clean these areas.
To avoid this, "spider guards" have conventionally been placed over the primary air intake openings. These spider guards have had some degree of success, but do not completely prevent spiders and other insects from entering through the fuel and air mixture exit ports in the burner head. Furthermore, the addition of "spider guards" provides an additional surface for debris to accumulate. Ultimately, cleaning of the gas orifice and gas mixing chamber is still required.
In addition, the cleaning procedure for this type of burner system to remove insects, spider webs and accumulated dust and dirt is relatively involved. The user is either forced to access the burner from below the mounting surface or, with some designs, one may be required to detach the entire burner from its mounting on the mounting-top for cleaning.
Another limitation of conventional burners is that the amount of combustion air provided to the burner must be adjusted when switching the type of gaseous fuel used; for example, propane versus natural gas. Also, during certain windy conditions, an adjustment to the combustion air intake is sometimes desired or necessary in order to achieve maximum performance of the burner. These adjustments are normally accomplished by adjusting the size of the opening or openings for the intake of combustion air. However, since these openings are mounted beneath the mounting surface on conventional burners, this adds to the inconvenience of having to make the adjustment.
While there are some burners which provide access to external parts of the burners by removing upper components thereof, most of these burners are not likely to provide sufficient structural stability when mounted to a barbecue with wheels. Such grills are occasionally moved over rough surfaces, such as lawns or spaced-deck boards. The lift-off components of these conventional burners in such instances may become partially or totally dislodged, resulting in an unacceptable condition.
Another problem unique to outdoor gas grills with conventional side burners is the potential for strong winds which blow the primary flame back into the air/fuel mixing chamber. This could cause melting of interior burner parts should they be manufactured out of aluminum.